1. Field of the Invention
The present invention relates to an image recording apparatus such as, for example, an ink jet printer, in which a liquid jetting head jetting liquid is mounted on a carriage unit, and particularly to an image recording apparatus of what is called an on-carriage type in which liquid cartridges are mounted on a carriage unit.
2. Description of the Related Art
There is known an ink-jet printer of what is called an on-carriage type in which an ink-jet head and ink-cartridges are mounted on a carriage configured to be reciprocatable in a casing. In an ordinary printer of the on-carriage type, an upper cover is provided on top of the casing. In order to change the ink cartridge, a user needs to open the casing by swinging the upper cover upward. Upon the operation of the upper cover, the carriage moves to a exchange position in the casing, and when the carriage stops at the exchange position, the user can access the ink cartridge mounted on the carriage from an upper side of a front surface of the casing (refer to, for example, Japanese Patent Application Laid-open No. 2009-248361). Further, in an ordinary printer of an on-carriage type, a plurality of nozzle arrays provided on a lower surface of the ink-jet head are disposed so as to line up in a scanning direction of the carriage. Further, right above the nozzle arrays, the plural ink cartridges disposed so as to line up in the scanning direction similarly to the nozzle arrays are mounted on the carriage.
For example, in a printer including a scanner of a flat bed type, an upper cover tends to become large. When the method for changing the ink cartridge described in Japanese Patent Application Laid-open No. 2009-248361 is applied to this printer, the operation of the upper cover at the time of the change becomes complicated. Therefore, there has been proposed a printer of an on-carriage type whose ink cartridge is changeable at a side of a casing (refer to, for example, Japanese Patent Application Laid-open No. 2002-036597).
According to Japanese Patent Application Laid-open No. 2002-036597, a carriage is reciprocatable in a scanning direction perpendicular to a transporting direction of a medium by being guided by a scanning shaft and one end side of the scanning shaft is extensible/contractible in the scanning direction. In a sidewall of the casing, a hole allowing the carriage to pass therethrough is formed at a position to which the scanning shaft is extended toward this one end side. At the time of the change of the ink cartridge, the carriage is moved toward the one end side. Then, the carriage passes through the hole while the scanning shaft is extending, and protrudes to the outside of the casing together with the scanning shaft. Thus, in the printer described in Japanese Patent Application Laid-open No. 2002-036597, since the exchange position can be located outside the casing, the operation of the upper cover is not required at the time of the change of the ink cartridge.
However, in the printer described in Japanese Patent Application Laid-open No. 2002-036597, the ink cartridges are mounted on the carriage so as to line up in the scanning direction, and at the time of the change of the ink cartridges, the ink cartridges are removed from/inserted to the carriage in the transporting direction. Because of this, the exchange position has to be located outside the casing as described above.
Specifically, in the printer described in Japanese Patent Application Laid-open No. 2002-036597, if the exchange position is located inside the casing, the ink cartridge closest to the hole hides the ink cartridges on a deeper side in spite of a user's attempt to access the carriages in the casing via the hole from the outside of the casing. The user is not capable of reaching the ink cartridges located on the deeper side, nor is he/she capable of even seeing them well. On the other hand, the user is capable of reaching the ink cartridge closest to the hole but has a great trouble in pulling/inserting the ink cartridge in the transporting direction while putting his/her hand in the casing via the hole.
Therefore, in order to enable the easy change of all the ink cartridges, the carriages have to be moved so that all the ink cartridges including the ink cartridge which is farthest from the hole in a state where the carriage is located inside the casing are exposed outside the casing. That is, the ink cartridge closest to the hole and thus has good accessibility greatly protrudes outside the casing. Setting the exchange position of the ink cartridges outside the casing results in poor space efficiency because of the need for reserving a space to allow the carriage located at the exchange position to escape thereto. Thus, in the conventional art, it is difficult to realize both the easy change of the ink cartridge and high space efficiency.